Safety and Construction Trailer

ABSTRACT

A safety trailer has semi-tractor hitches at both ends and a safety wall that is fixed to one side of the trailer. That side, however, can be changed to the right or left side of the road, depending on the end to which the truck attaches. A caboose can be attached at the end of the trailer opposite the tractor to provide additional lighting and impact protection. Optionally, the trailer can be equipped with overhead protection, lighting, ventilation, onboard hydraulics, compressors, generators and other equipment, as well as related fuel, water, storage and restroom facilities and other amenities.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/268,767, filed May 3, 2014, now abandoned, which is acontinuation of U.S. patent application Ser. No. 12/347,458, filed Dec.31, 2008, now abandoned, which is a continuation-in-part of U.S. patentapplication Ser. No. 11/209,460, filed Aug. 23, 2005, entitled “SAFETYAND CONSTRUCTION TRAILER”, now U.S. Pat. No. 7,572,022, which claimspriority to U.S. Provisional Patent Application Ser. No. 60/604,257,entitled “Safety and Construction Trailer,” filed on Aug. 25, 2004, eachof which are incorporated herein by this reference in their entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to the field of trailers andother types of barriers used to shield road construction workers fromtraffic. More specifically, the present invention discloses a safety andconstruction trailer having a fixed safety wall and semi tractor hookupsat both ends.

2. Statement of the Problem

Various types of barriers have long been used to protect roadconstruction workers from passing vehicles. For example, cones, barrelsand flashing lights have been widely used to warn drivers ofconstruction zones, but provide only limited protection to roadconstruction workers in the event a driver fails to take heed. Someconstruction projects routinely park a truck or other heavy constructionequipment in the lane between the construction zone and on-comingtraffic. This reduces the risk of worker injury from traffic in thatlane, but does little with regard to errant traffic drifting laterallyacross lanes into the construction zone. In addition, conventionalbarriers require significant time and effort to transport to the worksite, and expose workers to significant risk of accident while deployingthe barrier at the work site. Therefore, a need exists for a safetybarrier that can be readily transported to, and deployed at the worksite. In addition, the safety barrier should protect against lateralincursions by traffic from adjacent lanes, as well as traffic in thesame lane.

Solution to the Problem

In contrast to the prior art in the field, the present inventionprovides a safety trailer with a fixed safety wall and semi tractorhookups at both ends. The safety wall (and thus the entire trailer) canbe of a given length or it can be extendable, but the wall is “fixed” tothe platforms on one side of the trailer. That side, however, can bechanged to the right or left side of the road, depending on the end towhich the semi tractor attaches. This dual-ended, fixed-wall design thuseliminates the need for complex shifting or rotating designs, which areinherently weaker and more expensive, and which cannot support thevisual barriers, lighting, ventilation and other amenities necessary forproviding a comprehensive safety solution. The directional lighting andimpact-absorbing features incorporated at each end of the trailer and inthe caboose combine with the fixed wall and improved lighting to provideincreased protection for both work crews and the public, especially withever-increasing amounts of nighttime construction.

End platforms integral to the trailer's design minimize the need forworkers to leave the protected zone and eliminate the need for separatemaintenance vehicles by providing onboard hydraulics, compressors,generators and related power, fuel, water, storage and portable restroomfacilities.

Optional overhead protection can be extended out over the work area foreven greater environmental relief (rain or shine). The fixed wall itselfcan be made of any rigid material. The trailer carries independentdirectional and safety lighting at both ends and will work with anystandard semi tractor.

Optionally, an impact-absorbing caboose can be attached at the end ofthe trailer opposite the tractor to provide additional safety lightingand impact protection.

The present trailer is designed to provide road maintenance personnelwith improved protection from ongoing, oncoming and passing traffic, toreduce the ability of passing traffic to see inside the work area (tomitigate rubber-necking and secondary incidents), and to provide afully-contained, mobile, enhanced environment within which the workcrews can function day or night, complete with optional power, lighting,ventilation, heating, cooling, and overhead protection includingextendable mesh shading for sun protection, or tarp covering forprotection from rain, snow or other inclement weather.

Platforms can be provided at both ends of the trailer for hydraulics,compressors, generators and other equipment and supplies, includingportable restroom facilities. The trailer can be fully rigged withdirection and safety lighting, as well as lighting for the work area andplatforms. Power outlets are provided in the interior of the work areafor use with construction tools and equipment, with minimal need forseparate power trailers or extended cords. Both the caboose and thecenter underside of both end platforms provide areas for fuel, water andstorage. Additional fuel, water and miscellaneous storage space can beprovided in an optional extended caboose of like but lengthened design.

The trailer is designed to eliminate the need for separate lightingtrucks or trailers, to reduce glare to traffic, to eliminate the needfor separate vehicles pulling portable restroom facilities, to providebetter a brighter, more controlled work environment and enhanced safety,and to, among other things, better facilitate 24-hour construction alongour nation's roadways. Other applications include but are not limited topublic safety, portable shielding and shelter, communications and publicworks. Two or more trailers can be used together to provide a fullyenclosed inner area, such as may be necessary in multi-lane freewayenvironments, as shown for example in FIG. 4.

With significant shifts to night construction and maintenance, thepresent trailer provides a well-lit, self-contained, mobile safetyenclosure. Historical cones can still be used to block lanes, anddetection systems or personnel can be used to provide notice of anerrant driver, but neither offers physical protection or more than splitsecond warning for drivers who may be under the influence of alcohol orintoxicants, or who, for whatever reason, become fixated on theconstruction/maintenance equipment or lights and veer into or careenalong the same.

Studies have indicated that people are drawn to lights and distractions,and that they tend to steer and drive into what they are looking at.This is particularly hazardous for construction workers, especiallywhere cones and other temporary barriers are being deployed onmaintenance projects. Studies also indicate that lighting and equipmentmovement within a work zone are important factors in work site safety.Significant numbers of people are injured not only from errant vehiclesentering the work zone, but also simply by movement of equipment withinthe work area. The trailer is designed not only to keep passing trafficout of the work area, but also to reduce the amount of vehicles andequipment otherwise moving around within the work area. In terms oflighting, research indicates more is better. Current lighting is oftensomewhat removed from the location where the work is actually takingplace. Often, the lighting banks are on separate carts which themselvescontribute to equipment traffic, congestion and accidents within the jobsite. The trailer is designed to provide substantial lighting where itis needed. If the work moves, the lighting moves with the work area,rather than the work area moving away from the lighting. Mostimportantly, the safety barrier-front, back and side-will move alongtoo, providing simple but effective physical and visual barriers topassing traffic.

The trailer is intended to provide an increased level of physicalprotection both day and night, and to provide workers with aself-contained and enhanced work environment that provides them withbasic amenities such as restrooms, water, power, lighting, ventilationand even some possible heating/cooling and shelter. The trailer is alsodesigned to keep passing motorists from seeing what is going on withinthe work area and hopefully facilitate better attention to what is goingon in front of them. Hopefully, this will reduce both direct andsecondary incidents along such construction and maintenance sites.

SUMMARY OF THE INVENTION

This invention provides a safety trailer with semi-tractor hookups atboth ends and a safety wall that is fixed to one side of the trailer.That side, however, can be changed to the right or left side of theroad, depending on the end to which the semi-tractor attaches. A caboosecan be attached at the end of the trailer opposite the tractor toprovide additional lighting and impact protection. Optionally, thetrailer can be equipped with overhead protection, lighting, ventilation,onboard hydraulics, compressors, generators and other equipment, as wellas related fuel, water, storage and restroom facilities and otheramenities.

These and other advantages, features, and objects of the presentinvention will be more readily understood in view of the followingdetailed description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more readily understood in conjunction withthe accompanying drawings, in which:

FIG. 1 is a side perspective view of the safety trailer showing optionalmid and upper wall sections and associated lighting and ventilation.

FIG. 2 is a side perspective view of two embodiments of the safetytrailer showing the fixed outer wall as exposed to traffic, without themid and upper wall sections. This is referred to as the base trailerwith the lower wall only.

FIG. 3 is a side perspective view of an extendable version of the safetytrailer in its hyper-extended configuration with an additional extension30.

FIG. 4 is a perspective view showing two trailers 18, 20 parkedside-by-side to create a protected area 33 between the trailers.

FIG. 5 is perspective view showing a safety trailer with a caboose andsemi tractor attached. The trailer is open toward the viewer showing theinternal space and work area.

FIG. 6 is a perspective view showing a safety trailer with the canopy40, 35 extended and the caboose and semi tractor attached. The traileris open away from the view to show the exterior wall.

DETAILED DESCRIPTION OF THE INVENTION

Turning to FIG. 1, the trailer in the present invention is equipped withstandard semi-tractor hookups or hitches 1 at both ends. A tractor 27can be hooked to one end, and an impact-absorbing caboose 19 or 21 canbe hooked at the other, as illustrated in FIGS. 4, 5 and 6. By enablingthe tractor 27 to hook at either end, the trailer can incorporate arigid fixed wall 2 that is open to the right or left side of the roaddepending on the end on which the tractor is connected, as illustratedin FIGS. 4, 5 and 6. Thus, the side wall 2 and the ends of the trailerdefine a protected work area for road maintenance operations. Note thatthe tractor and caboose exchange trailer ends in FIGS. 5 and 6, thuschanging the side to which the wall 2 faces. In turn, the dual-hookup,fixed-wall design enables and incorporates platforms for equipment andstorage 12, and onboard power 11 and 16, lighting 6-8, ventilation,heating and cooling 9, relatively high shielding from driver views 3 and4, optional overhead protection 10, 35, 38 and 40, and in general, alarger and better work environment 37, day or night.

Safety Lighting. Large safety directional lights 6, 6 a and 6 b can beincorporated at each end of the trailer, along with light bars foremergency situations. This lighting is in addition to the lighting 23and 34 on the caboose 19 or 21, as shown in FIG. 5. All lighting can bedriven from the onboard power systems 16.

Onboard Power, Restrooms, and Equipment. Platforms at both ends of thetrailer provide area for hydraulics, compressors, generators 16,restroom facilities 17, and other equipment. Power can be provided viaboth PTO power from the tractor trailer as well as generator power 16from one of the end platforms. A power strip 11 along the inside lengthof the trailer provides convenient connections for tools and equipment,without the need for lengthy cords and separate generators. The portablerestrooms 17 can be loaded and removed as necessary. The platforms alsoprovide surface area for additional storage of equipment and supplies.

Fuel, Water, Storage and Counterbalances Under Platforms. Space isprovided for storage and/or for fuel and water tanks 12 in the protectedbelly of the trailer under the platforms. An optional elongated caboose21 can provide even more fuel, water and storage space. The outer areasof each platform can contain counterbalancing weights 14. For example,lead or other high-density materials can be used. Optional additionalcounterbalancing for the platform can be provided if necessary.

Trailer Stand. Standard trailer stands 15 are used at each end of thetrailer. While the tractor and caboose are switching ends, the trailerwill set on the stands (see e.g., FIGS. 1, 3 and 4). The stands 15 canalso be lowered to further stabilize the trailer when not in motion.

Work Area Lighting. An array of work area lights 8 are provided andcarried in the upper portion of the outer wall 2, as discussed below.The lighting 8 provides a well-illuminated area for the work crews. Fortraffic, the work area lighting 8 is largely obscured and hidden fromview. This eliminates the need for glaring generator lighting carts thathave to otherwise be pulled in place or pulled along at the job sitesand/or too frequently are some distance from the actual work area.Additional platform lighting 7 can also provided for the platform areasof the trailer.

Fans, Heating & Cooling. Fans 9 can also be mounted to the wall 2 toprovide supplemental ventilation. As noted below with respect to the topportion 5 of the outer wall 2, the fans 9 can be enclosed withprotecting screening rather than exposed as shown here. Optional heatingand cooling units (air-conditioning or misters) can be added to the fans9 to provide a bit cooler air when it is hot and a bit warmer air whenit is cold. Both heating and cooling units can be carried at one or bothends of the trailer and powered from the onboard sources 16.

Caboose. The standard caboose 19 shown in FIG. 2 serves as the rearwheels of the trailer and includes an impact-absorbing nose or crashattenuator 22 in case of an incident. The caboose 19 can also includedirectional safety lighting 23 and road lighting 34. The preferredembodiment of the caboose would include a steel frame and shell, withstandard semi-trailer axle or axles, wheels 39 and hookups for brakes,lighting and crash attenuation unit.

The caboose can be either steered independently or fixed in place tofunction like the rear wheels of a standard semi-trailer (e.g., FIG. 2).The preferred embodiment would be to use the short caboose 19 in a fixedconfiguration as shown in FIGS. 2, 4, 5 and 6. Any type of lockingmechanism can be used to fix the caboose 19. The preferred embodimentwould be to have caboose 19 carry a standard trailer plate like that ontractors to connect to the trailer, and to carry an additionalinterlocking tongue and groove or pin and groove connection for whichthe counterpart would be incorporated at both ends of the trailer.

When additional fuel, water and storage are required on an onboardbasis, the optional extended caboose 21 can be used. As depicted in FIG.5, optional guardrails 24 are available with brackets to allow for thequick and efficient repair of minor incidents. Use of the guardrails orsafety paint scheme would be matched to that on the trailer.

The nose section 22 of each caboose 19 can incorporate any of a varietyof crash attenuators or impact barriers, which in turn can be attachedto the caboose directly behind the axle and directly below the safetylighting. A bracket or plate attached to the frame of the caboose wouldprovide the connection for the crash attenuation unit.

The caboose 19 can carry standard traffic arrow directional lighting 23powered from the trailer's onboard power systems 16. The arrow would beswitched right or left, as appropriate, depending on what end of thetrailer the caboose is hooked to and the side on which the outer walland traffic is located. The lighting array can also include a flashinglight bar 6 a, as shown in FIG. 1, for use in case of emergencies, orother types of warning lights for oncoming traffic.

The caboose 19 has a connection at the front of the axle housing to runa hitch out under the nose for use with a standard ball hitch. With thehitch, a pickup or the semi-tractor can easily pull the caboose 19 tothe other end of the trailer or otherwise move it as necessary.

Outer Wall. The trailer has a rigid outer wall 2 and semi-tractorattachments 1 on both ends. Depending on the end to which thesemi-tractor attaches, the work area thus opens to the right or leftside of the road as shown in FIGS. 4, 5 and 6. The trailer utilizes afixed wall design in terms of the connections to the trailer hitches atboth ends, but can be either fixed or extendable in length, and can opento the right or left, depending on which end the semi-tractor attachesitself. No articulating mechanism is needed or used to swing the barrierfrom right to left side of the trailer. The fixed nature of the wall 2facilitates both simple and rigid operation, as well as nightconstruction and environmental enhancements discussed below.

For example, the outer wall 2 can be comprised of three levels: Lowerportion 3—a heavily constructed lower portion to provide a barrier totraffic and debris, Mid portion 4—an optional mid-portion of less weightand strength but also designed to provide a visual barrier, and Upperportion 5—an optional upper portion of relatively light constructionfitted and rigged for self-contained mobile lighting 8 for nightconstruction, as well as enclosed ventilation for fans 9 and optionalheating and cooling.

Lower Portion of the Outer Wall. The lower portion of the wall 3 isintended to come up approximately as high or higher than the hood of acar, pickup or SUV. Currently, the preferred embodiment is approximately4 feet. This portion of the wall can be constructed of any solidmaterial. Current preferred embodiments include heavy steel panels (or“sections”), panels fabricated from concrete or other rigid materials,reinforced steel or fabricated panels, and panels filled with sandfiller or other materials. For example, the exterior wall can be made of20 foot long 0.375 inch steel panels specially folded or reinforced andbolted to the platform or to each other to form an elongated fixed wall.Three such wall panels can be attached to form a 60 foot wall betweenthe platforms. The trailer thus described can be made longer or shorterby increasing or decreasing the number of panels used in the wall. Thewall panels can be detached and placed on top of the platforms for longdistance or higher speed transport. The platforms can be bolted andattached directly to each other when all panels are removed. Theinterior of the wall (i.e., the side toward the workers) can be open toallow internal access for inspection and repairs in the case of anincident. Either platform, or any applicable section of the wall couldbe removed and replaced in the event of an incident.

Another example would be to use the same panels to form walls with 6-12inches of interior space into which sand in loaded. Bracing would bewelded to the exterior wall, to which the interior wall would be bolted.The bracing would provide support and a consistent depth of the wallsbetween which sand would be filled. As above, sections of the wall couldbe removed and replaced in the event of an incident.

Another example would be the use of one or more panels or sectionsfabricated from concrete or other rigid materials. Connections to theadjoining sections, as well as the upper portions of the wall and bothends of the trailer would be integrated into the fabricated wall. Anysecure, rigid connection can be used. The preferred embodiment forconnecting the sections (if more than one is used) would be metalbrackets in something of an H shape, where the two arms of the open endsfit some length along the exterior of each section and affix firmly withmultiple cross-bolts. Again, sections of the wall could be removed andreplaced in the event of an incident.

Another example would be the use of a solid reinforced steel surfacerunning the length of the trailer. The preferred embodiment of such adesign would involve a heavy steel outer skin welded or bolted togetherand reinforced with bracing on the back (or inner) side. Assembly couldalso be by overlapping joints and/or such other means as would create asolid wall running the length of the trailer.

A power strip 11 runs along the exposed surface of the interior wall toprovide outlets for equipment and tools. The power strip 11 is removableshould a section of the wall need to be removed for inspection orrepairs, or should a section of the wall need to be replaced.

The exterior of the wall can be fitted and supplied with brackets forguard rails 24, such as additional overlaying lengths of heavy steel orconventional guard rails such as those used along roadways. Such guardrails 24 may protect the main wall from minor incidents, such as when avehicle angles into and scrapes along the side of the trailer, and maybe quicker and easier to replace. The steel or fabricated panels mayalso contain special folds providing raised surfaces and added strengthand rigidity, which also can server as an integral type of guard rail.

The exterior wall, as thus described embodies what is sometimes referredto as a “fixed wall” design. It is a fixed wall in that it is always ononly one side of the trailer, although the work area can open to theright or left side of the road depending on the end to which the tractorand caboose are attached, as in FIGS. 4, 5 and 6. The length of the walland thus the overall trailer can be longer or shorter depending on thenumber of panels or sections installed, or the length to which the wallis otherwise made.

The fixed wall design allows for significant economies in manufacture,maintenance and repair. For example, sections or panels of steel wallcan be formed at the steel mills by large presses and preformed andsized to specifications. In the case of an incident where a vehiclestrikes the wall or one of the platforms, the same can be inspected andthe platform and/or one or more sections of the wall can replacedrelatively quickly and economically if necessary.

The fixed wall design also provides a base upon which optional visualbarriers (e.g., the mid wall 4) and lighting and ventilation (the upperwall 5) can be added. The preferred embodiment of the mid and upperwalls would again follow the modular or sectional design of the lowerwall, and affix both to the lower wall and horizontally to each othervia a series of bolts, pins and/or other connections. Connections areprovided for power, lighting and other amenities. The wall can bedesigned to extend vertically to any desired height to provide a visualbarrier between passing motorists and the work area.

In addition to the fixed length version of the trailer 18, an extendableversion 20 with multiple sections can also be provided. The extendabletrailer 20 would allow for a shorter overall length while drivingbetween destinations, and would provide some benefits in terms ofmobility. One embodiment for the extendable version of the trailer 20would involve an extendable crane type extendable steel housing andinner core 29 as represented in FIGS. 3 and 4. The trailer can beextended and contracted hydraulically or by simply having thesemi-tractor pull slowly forward or back slowly up. A latch would lockin place when the trailer reaches full length. A simple, but heavyhook-type latch could be used where the point goes into a groove to lockthe trailer length before the sections fully separate. One or moresafety cross-bolts further lock the trailer length.

The extendable version of the trailer could be further lengthened byadding additional wall extensions 30 as shown in FIG. 3. The preferredembodiment for doing so would be to hold open the locking mechanism thattypically catches when the trailer is being separated. To the extent thelocking mechanism is manually held open, the latch will not catch andthe two ends of an extendable trailer can be separated. Each separatingend would need to be supported in some way, such as with a steel rollerbrace positioned under each separating end before they are fully pulledapart. The sections would then be pulled apart far enough to allow anadditional extension 30 to be rolled into place and attached to bothends. The additional extension 30 may itself also have an extendableinner core similar to that used on the trailer 29, which when connectedat both ends, can be further pulled apart until the latch locks and thecross-bolts are inserted. Wheels on the extension would be themselveslocked once in place.

The extending inner core of the extendable trailer 29, as well as anyextendable core of an additional extension, would be heavily constructedof any solid material. The preferred embodiment of the inner core wouldbe steel casing filled with concrete or sand for further weight andstructural rigidity. The extendable version of the trailer can alsoincorporate offset upper portions of the outer wall 20 a to allow themid and top levels of the respective sections to parallel each otherwhen compressed and still provide the maximum length of lighting thatcan be carried with the compacted trailer 20. Similar lighting andventilation 20 b can be mounted at intervals along the top of anyadditional extensions that may be inserted.

The clearance to the bottom of the wall, the height of the bottomportion of the wall, and the length of the wall can be made to customerspecifications. The preferred embodiment would include a clearance of 12inches, a height of 4 feet, and a length of 75-100 feet for Departmentof Transportation road construction purposes, subject to the issuance ofapplicable permits and applicable road and condition characteristics.

Mid-Portion of Outer Wall. The optional mid-portion of the outer wall 4consists of mesh or cable-reinforced meshing 36 or solid side panels 25.The mesh 36 would be relatively opaque to passing traffic at an angleand be used to deter traffic from looking into the work area and beingdistracted (FIG. 5). The preferred current embodiments involve meshfabric 36 similar to that used on top of industrial vehicles (e.g.,semi-dump trucks), with or without a cable-backing similar to that usedat race tracks. Other and stronger mesh materials can be used. Thecabling is provided where additional protection is desired to protectworkers from the risk of work area intrusions from airborne vehicles ordebris in the case of an incident. The mesh and cables retract to oneend of the trailer or to one end of each section of the wall, with onepossible embodiment being simply manually-operated winch-type rollers.While opaque to oncoming traffic, the mesh and cabling dissipate sidewind resistance and allow for additional side breezes in hot weather.

The mesh and cable can be retracted and replaced with side panels 25during inclement weather or as desired. The side panels 25 can be madeof any solid material. The preferred current embodiment is to usemultiple relatively thin and light aluminum or steel panels that can beattached and affixed with the assistance of a pay-loader or similarequipment. Hinges (top, bottom or side) can be used with the panels toprovide increased convenience for opening and closing off the outer wallin this manner.

Upper Portion of the Outer Wall. The optional upper portion of the outerwall 5 may contain alternating arrays of lights 8 and fans 9 toilluminate and help improve environmental conditions in the work area.Both can be run from the onboard power options 16 (generator orsemi-tractor power take-off), as will the power strip along the lowerportion of wall 11. The fans, for example, can be enclosed withprotective screening. Optional heating and cooling units(air-conditioning or misters) can be added to the fans to provide a bitcooler air when it is hot and a bit warmer air when it is cool. Bothheating and cooling units can be carried at one or both ends of thetrailer and powered from the onboard sources 16.

The very top of the wall (above the lights and fans) can carry optionaloverhead protection in the form of extendable mesh 35 or tarp canopies40 (FIG. 6). Offset retractable arms 10 at each end of the trailer canbe extended out over portions of the work area to roll out and providemesh protection from the sun or tarp protection from rain, snow andother inclement weather. Optional mid-trailer braces can be used tosupport and strengthen the retractable beams once deployed. It isanticipated that the canopy would not be deployed much of the time, asmobility, convenience, problematic winds, vehicular traffic inside thework area and other factors may make such additional protectionimpractical.

The mid and upper walls are optional and the trailer can be used withoutthe as shown in FIG. 2. While research indicates that the mid and upperportions provide important safety enhancements, they may be deemedunnecessary where, for example, the trailer is used exclusively for dayconstruction. Users in such cases may prefer only the base trailer witha fixed lower wall, caboose, safety lighting and crash attenuation, asshown in FIG. 2. Where the mid and upper walls are not deployed, a shortriser of solid or flexible material may be used to raise the visualbarrier such as to a level of about 5 feet and/or consistent with theheight of the platforms. Higher visual barriers can be provided.

Additional hitch options can also be employed. The preferred hitchembodiment is the standard semi tractor trailer connection as disclosedabove, but other hitch options can be incorporated including withoutlimitation fifth wheel designs and special hitch configurations forconstruction and other heavy equipment such as graders, plows and othertrucks which might otherwise be available for service.

Additional caboose options can also be employed. The preferred cabooseembodiment is as discussed above, but a permanently affixed cabooseand/or rear axle can be used if and to the extent the user so desires.In such cases, the user would not be able to switch the ends to whichthe tractor attaches, and thus would not be able to change the side towhich the work area opens, but the user may have more than one trailerdedicated for different applications and not require such flexibility.

The trailer is designed to be heavy enough to withstand a front or rearimpact, a glancing blow or more direct side impact, and yet providereasonable protection for the work area inside. In that regard, the lowcenter of weight is intended to provide a relatively immobile fortress.The wall itself, as well as the caboose, is intentionally meant to beexpendable and replaceable in the event of an incident. Steel panels canbe easily inspected, removed and replaced. Sections can be cut andre-welded. Interior wall bracing refortified. Sand can be refilled andfabricated sections can be replaced.

The trailer was designed to provide a physical barrier, improve lightingand ventilation, reduce the number of construction vehicles andequipment needed inside the work area, and to reduce the ability ofpassing traffic to see or err into the work area, all factors studiesindicate are important for increasing the safety of the work crews andthe public at large. The trailer design intentionally and importantlystrives to provide these safety enhancements in a convenient packagewhile keeping overall design simple and relatively economical tomanufacture, maintain and repair.

While specifically conceived and developed for road construction andmaintenance crews following the tragic death of two employees of theColorado Department of Transportation, the trailer can be used for otherpurposes as well. No limitation is place on the purposes for which it isdeployed.

The outfitting of the trailer can be modified. For example, the trailercan be used with or without the mid and upper walls; different crashattenuators can be attached to and used with the caboose; hydraulics,compressors, and generators can be separately provided or replaced bythe user; the overhead canopy protection can be omitted; duplicatedirectional lighting on the trailer and the caboose can be consolidatedif deemed unnecessary. These and other changes can be made, butfundamentally, the present invention offers a new level of physicalprotection and safety, day and night.

The above disclosure sets forth a number of embodiments of the presentinvention described in detail with respect to the accompanying drawings.Those skilled in this art will appreciate that various changes,modifications, other structural arrangements, and other embodimentscould be practiced under the teachings of the present invention withoutdeparting from the scope of this invention as set forth in the followingclaims.

1. A safety trailer assembly, comprising: (a) first and secondplatforms, the first platform comprising a hitch member to removablyattach to a motorized vehicle; (b) a rigid wall defined by at least afirst side of each of the first and second platforms, the rigid wallenclosing a work area and being configured to withstand an impact frommotorized traffic; wherein: a side of the enclosed work area is open toenable vehicular and personnel access to the enclosed work area and topermit personnel to access a road surface underlying the enclosed workarea; and the rigid wall further comprises at least one wall panelextending between and attached to the first and second platforms,wherein the at least one wall panel comprises a heavily constructedrigid lower portion to provide a barrier to traffic, and wherein thelower portion extends from at or near ground level to a height at leastas high as a hood of a car, pickup or sports utility vehicle.
 2. Theassembly of claim 1, wherein the at least one wall panel is fixedrelative to the first and second platforms and the at least one wallpanel does not shift or articulate relative to the first and secondplatforms.
 3. The assembly of claim 1, wherein the at least one wallpanel does not rotate relative to the first and second platforms.
 4. Theassembly of claim 1, further comprising a plurality of: a crashattenuator; on-board hydraulics; a compressor: a power generator andpower hookups for equipment; a portable restroom facility; a heating andcooling system; and a ventilation system.
 5. The assembly of claim 1,further comprising a crash attenuator on an end of the assembly oppositethe motorized vehicle hitch member and onboard directional lighting toilluminate the work area.
 6. The assembly of claim 1, further comprisingfirst and second hitch members, respectively, at the first and secondplatforms and a wheeled caboose configured to removably engage the firstand second hitch members, wherein, in a first mode, the motorizedvehicle is attached to the first hitch member and caboose to the secondhitch member and, in a second mode, the motorized vehicle is attached tothe second hitch member and a caboose to the first hitch member, wherebythe right wall can open to the first or second side of a road.
 7. Theassembly of claim 1, further comprising a counterbalancing weight tocounterbalance a weight of the rigid wall.
 8. The assembly of claim 1,further comprising a caboose removably attached to the second platform,the caboose comprising at least one axle, wheels, brakes, and a crashattenuation unit.
 9. The assembly of claim 8, wherein the caboosecomprises a hitch connection operable to engage a hitch engaging memberof the motorized vehicle to reposition the caboose when disengaged fromthe second platform.
 10. The assembly of claim 8, wherein the caboose issteered independently.
 11. The assembly of claim 8, wherein the cabooseis fixed in place to function like the rear wheels of a standardsemi-trailer.
 12. The assembly of claim 9, wherein the caboose carries astandard trailer plate like that on tractors to connect to a trailer.13. The assembly of claim 12, wherein the caboose carries an additionalinterlocking tongue and groove connection for which the counterpartwould be incorporated at both ends of the trailer.
 14. The assembly ofclaim 12, wherein the caboose carries an additional interlocking pin andgroove connection for which the counterpart would be incorporated atboth ends of the trailer.
 15. The assembly of claim 1, wherein the atleast one wall panel is made of 20 foot long, 0.375 inch thick steelplate.
 16. The assembly of claim 15, wherein the steel plate is foldedor reinforced.
 17. The assembly of claim 1, wherein the at least onewall panel has 6-12 inches of interior space into which sand is loaded.18. The assembly of claim 17, wherein bracing is disposed in theinterior space.
 19. The assembly of claim 1, wherein the at least onewall panel is fabricated from concrete.
 20. The assembly of claim 1,wherein the at least a first and second sides of the first and secondplatforms comprises additional wall sections positioned between thefirst and second platforms and wherein the first side is substantiallyplanar to direct a motorized vehicle impacting the first side away fromthe work area.